The invention relates to a circuit architecture for an integrated circuit, and in particular to an arrangement of arithmetic/logic units, selection units, and control units in such an architecture.
As the use of integrated circuits has been growing for years in all areas of electronics, tremendous efforts have been made by manufacturers to achieve efficient realizations of integrated circuits in the shortest possible time. The electronics industry has been continually driven by the need to increase performance and reduce costs, while improving the features of the integrated circuits. Additional requirements include the need to optimize the circuit architectures offered—implemented, for example, as integrated circuits—in terms of surface area requirement, power consumption, and power loss.
Many of the requirements are met through the use of newer, faster, and cheaper technologies. These new technologies enable a larger number of functions and features to be combined on a single piece of silicon. Functions previously located on separate chips can now be offered in a single system integrated within a single chip. Due to the complexity and high degree of specialization within the various areas of application for integrated circuits, increasing use is being made of application-specific integrated circuits. Application-specific integrated circuits can then be subdivided into user-programmable components and components fabricated for specific applications, where the latter, although highly specialized, are nevertheless fabricated to execute fixed specified functions and are not configurable by the user.
In many areas, however, there exists precisely the need to supply integrated circuits, the architecture of which provides the user with the flexibility of reacting quickly to new requirements. These integrated circuits, also identified as user-programmable components, involve universal elements, the fabrication of which is implemented by the manufacturer on a standardized basis, but which are defined in terms of their ultimate function only by a programming or configuration performed by the user. See reference: G. Umbach, 1966, Kaiserslautern, dissertation, “Optimization of Macrocell-Based Sea-of-Gates Architecture for Communications Technology.”
One representative example of a field of application for these components configurable by the user is the automotive industry which demands even shorter product development cycles. For example, even today there are more than seventy control systems in use in a luxury-class automobile. As a result, the share of electronics and software has risen to over 30% within the value-added chain. However, design tasks have also become even more demanding as a result of the increasing complexity and number of functions to be performed by an electronic system. Then there is the additional demand for a short time span between the start of development and market maturity (time-to-market) which must succeed without costly supplemental corrections to the final product within its application environment. This results in corresponding requirements in terms of high flexibility and simultaneous inexpensive fabrication of these components. Examples of control systems using these types of components in automotive engineering include control devices for the engine, transmission, ESP, air suspension, automatic climate control, sound system, parking aids, instrument clusters, and data buses.
The integrated circuits fabricated for specific applications can be further subdivided into designs completely configurable by the user and designs partially configurable by the user. In the case of designs completely configurable by the user, all the design steps are accordingly parametrized and optimized, and there are no restrictions on the design or on the configuration of the subsequent interconnection circuitry based on individual customer requirements. In the case of these designs which are partially configurable by the user, as are those covered by this patent, the user exploits prefabricated and pre-wired basic structures which can then be further interconnected in a configurable manner by the user according to his requirements. It is obvious that these designs, which are partially configurable by the user, have advantages in terms of their surface area requirement on a chip, power consumption, and production costs relative to designs that are completely and freely configurable for which implementation as an integrated circuit is significantly more complex and thus, among other things, more cost-intensive.
One example of integrated circuits with prefabricated basic structures involves hardwired hardware solutions in which the configurability is restricted to parametrization by registers. Additional examples include Field Programmable Gate Arrays (FPGAs) and Application-Specific ICs (ASICs) which have, in part, basic structures in macrocells to increase efficiency in terms of the required silicon surface of the chip, power consumption, and cost. Another example that could be mentioned for the use of prefabricated basic structures involves so-called streaming units which, however, in many cases do not have the requisite flexibility.
One disadvantage of the listed examples of prior art integrated circuits having prefabricated basic structures according to the prior art is that, while these largely fulfill the requirements in terms of small surface area on the chip, low power consumption, and low cost, from the perspective of most current requirements, they do not adequately meet the ever-increasing demands for flexibility in terms of the configurability of these inexpensive integrated circuits.
Therefore, there is a need for an arrangement of arithmetic/logic units, selection units, and control units in a circuit architecture which, while retaining the advantages of small surface requirement on a chip, low power consumption, and low cost, has an increased degree of flexibility of configurability relative to the prior art.